Oil extended ultra high molecular weight elastomers

ABSTRACT

Elastomer compositions comprising (A) ultra high molecular weight copolymer compositions of 1,3-conjugated dienes and aromatic vinyl compounds having a weight average molecular weight of greater than about 1,000,000 and (B) oil are described. The ultra high molecular weight copolymer compositions which are also characterized as having an intrinsic viscosity in tetrahydrofuran of at least about 4.0 may be obtained by a process which comprises polymerizing a 1,3-conjugated diene and a vinyl aromatic compound in a hydrocarbon solvent in the presence of a trimetalated 1-alkyne catalyst which comprises the reaction product of a 1-alkyne containing at least 4 carbon atoms, an organo metallic compound R°M and a 1,3-conjugated diene wherein R° is a hydrocarbyl group, M is an alkali metal, the mole ratio of R°M to 1-alkyne is about 3:1 and the mole ratio of conjugated diene to 1-alkyne is from about 2:1 to about 30:1. The oil extended elastomer compositions of the present invention preferably contain large amounts of oil such as 80 parts or higher per 100 parts of copolymer.

This application is a continuation of application Ser. No. 07/586,064,filed Sep. 21, 1990, now U.S. Pat. No. 5,260,370.

TECHNICAL FIELD OF THE INVENTION

This invention relates to elastomer compositions comprising (A) ultrahigh molecular weight copolymers of conjugated dienes such as1,3-butadiene and aromatic vinyl compounds such as styrenes and (B)extender oil. More particularly, this invention relates to suchcompositions wherein the copolymers are prepared using a trimetalated1-alkyne catalyst.

BACKGROUND OF THE INVENTION

The incorporation of oil into elastomeric compositions is known toimprove the properties of the elastomer composition. The incorporationof large amounts of oil is desirable since it generally results inhigher hysteresis loss. In some instances, however, attempts to includelarge amounts of oils into elastomeric compositions result in loss ofother desireable properties such as rupture strength, wear resistance,and heat resistance.

The polymerization of conjugated dienes such as 1,3-conjugated dienes toform elastomeric homopolymers and copolymers utilizing various initiatorsystems is known. For example, such polymerizations can be initiatedwith organometallic compounds wherein the metal is a Group I metal suchas lithium. These polymers and copolymers of conjugated dienes areuseful for tire rubbers, molded rubber goods, molding compounds, surfacecoatings, etc.

Various organometallic compounds have been described in the literatureas useful in the polymerization and copolymerization of conjugateddienes. Among the catalysts which have been proposed are various alkalimetal acetylides. For example, U.S. Pat. No. 3,303,225 describes the useof metalated 1-acetylenes as active catalysts in the polymerization ofvinylidene-containing monomers. Alkali metal acetylides containing oneor more metal atoms are prepared by reacting an organo alkali metalcompound with an acetylene under conditions to effect step-wisereplacement of, first, the acetylenic hydrogen atom, and, second, thehydrogen atoms attached to the carbon atom which is alpha to theacetylenic linkage.

U.S. Pat. No. 4,677,165 describes rubber compositions usefulparticularly for tire treads which comprise: a styrene-butadienecopolymer rubber prepared by random copolymerization of styrene with1,3-butadiene by solution polymerization techniques utilizing an organiclithium compound as catalyst; from 80 to 250 phr of carbon black havinga surface area of 100 to 400 m² /g; and 30 to 280 phr of an aromaticoil. It is essential that the styrene-butadiene copolymer satisfies sixrequirements as identified in the specification and claims including thepresence of one or more specific groups introduced into a molecularterminal or chain of the copolymer.

U.S. Pat. No. 2,964,083 describes curable rubber tire tread stock andpneumatic tires having a tread portion made of such stock. The treadstock comprises a copolymer containing a major amount of a conjugateddiolefinic compound and a minor amount of a copolymerizable monoolefiniccompound such as styrene, a fine reinforcing high abrasion carbon blackand at least 30 parts by weight of a compatible soft oil per 100 partsby weight of the copolymer.

Styrene-butadiene elastomers comprising blends of differentstyrene-butadiene copolymers are described as being useful for treads ofhigh performance tires in U.S. Pat. No. 4,866,131. The elastomers can beextended with oil to increase the hysteresis loss value. Aromatic oilshaving a viscosity gravity constant according to ASTM D-2501 in therange of 0.900 to 1.100 are described as suitable. The use of a lowtemperature plasticizer ester and/or a naphthenic or paraffinic softenerto improve the properties of carbon black filled styrene-butadienerubbers is described in U.S. Pat. No. 4,748,199.

U.S. Pat. No. 4,791,178 describes rubber compositions for use in tireswhich comprise certain mixtures of copolymers of a conjugated diene andmonovinyl aromatic hydrocarbons. To obtain high hysteresis loss, thepatentees suggest that an extender oil be blended into rubbercompositions in amounts of from 30-200 parts by weight based on 100parts by weight of the rubber component. Amounts of from 50 to 200 partsof oil are preferred. The use of 60 to 200 parts by weight of carbonblack having an average particle size of not more that 300 Å also isdisclosed as producing rubber composition with high hysteresis loss.

SUMMARY OF THE INVENTION

Elastomer compositions comprising (A) ultra high molecular weightcopolymer compositions of 1,3-conjugated dienes and aromatic vinylcompounds having a weight average molecular weight of greater than about1,000,000 and (B) oil are described. The ultra high molecular weightcopolymer compositions which are also characterized as having anintrinsic viscosity in tetrahydrofuran of at least about 4.0 may beobtained by a process which comprises polymerizing a 1,3-conjugateddiene and a vinyl aromatic compound in a hydrocarbon solvent in thepresence of a trimetalated 1-alkyne catalyst which comprises thereaction product of a 1-alkyne containing at least 4 carbon atoms, anorgano metallic compound R°M and a 1,3-conjugated diene wherein R° is ahydrocarbyl group, M is an alkali metal, the mole ratio of R°M to1-alkyne is about 3:1 and the mole ratio of conjugated diene to 1-alkyneis from about 2:1 to about 30:1. The oil extended elastomer compositionsof the present invention preferably contain large amounts of oil such as80 parts or higher per 100 parts of copolymer.

BRIEF DESCRIPTION OF THE DRAWING

The drawing is a graph of torque versus time identifying the pointsML_(in), ML₁₊₄, AL₈₀ and AL₁₊₄₊₅ used in determining percent relaxationof the copolymers used in the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The elastomer compositions of the present invention comprise (A) anultra high molecular weight copolymer composition of 1,3-conjugateddienes and aromatic vinyl compounds having a weight average molecularweight of greater than about 1,000,000 and (B) oil. In preferredembodiments, the elastomer compositions of the present invention willcontain large amountsof oil such as from about 30 to about 300 parts byweight of oil per 100 parts by weight of the copolymer (A).

(A) Ultra High Molecular Weight Copolymers.

The copolymers useful in the present invention are of the type generallyreferred to as ultra high molecular weight copolymer compositions. Inparticular, the copolymer compositions are obtained by copolymerizing1,3-conjugated dienes with aromatic vinyl compounds. The ultra highmolecular weight copolymer compositions obtained in accordance with thepresent invention are essentially free of gel and are furthercharacterized as having a weight average molecular weight of greaterthan about 1,000,000. Ultra high molecular weight copolymer compositionscan beprepared by the method of the present invention having a weightaverage molecular weight of greater than 1,100,000. Other characterizingfeatures of the ultra high molecular weight copolymers include inherentviscosity, dilute solution viscosity and percent relaxation asdetermined using a Mooney viscometer. In one embodiment, the copolymercompositions are characterized as having an intrinsic viscosity (η) intetrahydrofuran of at least 4.0, and in another embodiment, thecopolymers have an intrinsic viscosity in tetrahydrofuran of at leastabout 4.5.

The ultra high molecular weight compositions useful in the invention mayalso be characterized in terms of percent relaxation as determined by aprocedure which will be discussed more fully below. In one embodiment,thecompositions are characterized by percent relaxation values of atleast about 30% to 100%, and more particularly relaxations of from about30% to about 70%.

The ultra high molecular weight compositions also may be characterizedas having a dilute solution viscosity in toluene of at least about 3.5dl/g,and in one embodiment, the copolymers will have a dilute solutionviscosityof at least about 4.0 dl/g. The ultra high molecular weightcopolymers generally will be characterized by an Mw/Mn of at least about1.9, more often, between about 2.0 or 2.5 and 5.0.

The copolymer compositions also may be characterized by their molecularweight distribution. The copolymer compositions contain a large fractionof copolymer having a number average molecular weight of greater than1,000,000 and a small fraction of copolymer having a number averagemolecular weight of less than 100,000. In one embodiment of the presentinvention, the copolymer is characterized as comprising at least 30%,preferably more than about 35% by weight of a fraction having a numberaverage molecular weight of greater than 1,000,000, and less than 8% byweight, preferably less than 5% by weight, of a fraction having a numberaverage molecular weight of less than 100,000.

The copolymer compositions useful in the present invention arecopolymers of a 1,3-conjugated diene monomer and an aromatic vinylmonomer. The relative amount of conjugated diene and aromatic vinylmonomers included in the copolymers may be varied over a wide rangedepending upon the desired copolymer properties. Thus, the amount ofconjugated diene in the copolymer may vary from 10 to about 90% byweight and the amount of aromatic vinyl compound from about 10 to about90% by weight. More generally, the copolymers will comprise from about50 to about 90%, preferably from about 50 to about 80% by weight of theconjugated diene and from about 10 to about 50% by weight, morepreferably from about 20 toabout 50% by weight of the aromatic vinylcompound.

Monomers.

The conjugated diene monomers useful in preparing the copolymersgenerally are 1,3-dienes, and they contain from 4 to 12 carbon atoms andpreferably from 4 to 8 carbon atoms per molecule. Examples of thesedienes include the following: 1,3-butadiene, isoprene,2,3-dimethyl-1,3-butadiene, 1,3-pentadiene (piperylene),2-methyl-3-ethyl-1,3-butadiene, 3-methyl-1,3-pentadiene,2-ethyl-1,3-pentadiene, 1,3-hexadiene, 2-methyl- 1,3-hexadiene,1,3-heptadiene, 3-methyl-1,3-heptadiene, 1,3-octadiene,3-butyl-1,3-octadiene, 3,4-dimethyl-1,3-hexadiene,3-n-propyl-1,3-pentadiene, 4,5-diethyl-1,3-butadiene,2,3-di-n-propyl-1,3-butadiene, 2-methyl-3-isopropyl- 1,3-butadiene, andthe like. Among the dialkyl butadienes, it is preferred that the alkylgroups contain from 1 to 3 carbon atoms. Conjugated dienes containingalkoxy substituents along the chain can also be employed, such as2-methoxy-1,3-butadiene, 2-ethoxy-3-ethyl-1,3-butadiene, and2-ethoxy-3-methyl- 1,3-hexadiene.

The aromatic vinyl compounds include styrene, 1-vinyl-naphthalene,2-vinylnaphthalene, and alkyl, cycloalkyl, aryl, alkaryl, aralkyl,alkoxy,aryloxy, and dialkylamino derivatives thereof in which the totalnumber of carbon atoms in the combined substituents is generally notgreater than 12. Examples of these aromatic monomers includep-methylstyrene, alpha-methylstyrene, 3,5-diethylstyrene,4-n-propylstyrene, 2,4,6-trimethylstyrene, 4-dodecylstyrene,3-methyl-5-n-hexylstyrene, 4-cyclohexylstyrene, 4-phenylstyrene,2-ethyl-4-benzylstyrene, 4-p-tolylstyrene, 2,3,4,5-tetramethylstyrene,4-(4-phenyl-n-butyl)styrene,3-(4-n-hexylphenyl)styrene,4-methoxystyrene, 3,5-diphenoxystyrene, 2,6-dimethyl-4-hexoxystyrene,4-dlmethylaminostyrene, 3,5-diethylaminostyrene,4-methoxy-6-di-n-propylaminostyrene, 4,5-dimethyl-1-vinylnaphthalene,3-ethyl-1-vinylnaphthalene, 6-isopropyl-1-vinyl-naphthalene,2,4-diisopropyl-1-vinyl-naphthalene,3,4,5,6-tetramethyl-1-vinylnaphthalene,3,6-di-n-hexyl-1-vinyl-naphthalene, 8-phenyl-1-vinyl-naphthalene,5-(2,4,6-trimethylphenyl)-1-vinylnaphthalene,3,6-diethyl-2-vinylnaphthalene, 7-dodecyl-2-vinylnaphthalene,4-n-propyl-5-n-butyl-2-vinylnaphthalene, 6-benzyl-2-vinylnaphthalene,3-methyl-5,6-diethyl-8-n-propyl-2-vinyl-naphthalene,4-p-tolyl-2-vinylnaphthalene, 5-(3-phenyl-n-propyl)-2-vinylnaphthalene,4-methoxy-1-vinylnaphthalene, 6-phenoxyl-1-vinylnaphthalene,3,6-dimethylamino-1-vinylnaphthalene, and the like. Other examples ofvinyl substituted aromatic compounds are found in U.S. Pat. No.3,377,404,the disclosure with respect to which is incorporated herein byreference. Preferred aromatic vinyl compounds include the styrenes,particularly, styrene.

Preferred copolymers are those obtained from 1,3-butadiene, isoprene orpiperylene with styrene. More particularly, copolymers of 1,3-butadieneand styrene are preferred.

Catalyst

In one embodiment, the ultra high molecular weight copolymers useful inthepresent invention are obtained by polymerizing a 1,3-conjugated dieneand an aromatic vinyl compound in the presence of a catalyst which is atrimetalated 1-alkyne. The trimetalated 1-alkyne catalysts arecharacterized by the formula ##STR1##wherein R is a hydrocarbyl group, Mis an alkali metal, R¹ is a divalent oligomeric hydrocarbyl groupcomprising moieties derived from a 1,3-conjugated diene, and the totalnumber moieties derived from a 1,3-conjugated diene in all of the R¹groups in Formula I is from about 2 to about 30.

The hydrocarbyl group R may be a saturated aliphatic, saturatedcycloaliphatic or an aromatic group generally containing up to about 20carbon atoms. In one embodiment, R is an alkyl group containing from 1to 15 carbon atoms. In another embodiment, R is an alkyl groupcontaining 1 to 6 carbon atoms. In yet another embodiment, R is an alkylgroup containing from about 3 to 9 carbon atoms. M is an alkali metalincluding lithium, sodium, potassium, rubidium, cesium and francium.Lithium, sodiumand potassium are preferred alkali metals, and lithium isthe most preferred alkali metal.

The substituent R¹ is a divalent oligomeric hydrocarbyl group comprisingmoieties derived from a 1,3-conjugated diene. The conjugated dienes maybe any of a variety of 1,3-conjugated dienes including those containingfrom 4 to 12 carbon atoms, and preferably from 4 to 8 carbon atoms permolecule. Specific examples of the conjugated dienes include:1,3-butadiene; isoprene; 2,3-dimethyl-1,3-butadiene;1,3-pentadiene(piperylene); 2-methyl-3-ethyl-1,3-butadiene;3-methyl-1,3-pentadiene; 1,3-hexadiene; 2-methyl-1,3-hexadiene;1,3-heptadiene; 1,3-octadiene; etc. In one preferred embodiment, themoieties of the oligomeric group R¹ are derived from 1,3-butadiene,isoprene or piperylene.

The number of moieties derived from a conjugated diene in the R¹ groupsof the composition of Formula I may be varied over a range of from 2 toabout 30. Generally, the total number of moieties derived from aconjugated diene in the two R¹ groups in the composition of Formula Iisfrom about 3 to about 30. In one preferred embodiment, the total numberof conjugated diene derived moieties in all of the R¹ groups in thecomposition of Formula I is from about 8 to about 20. The number ofmoieties derived from a conjugated diene in the oligomeric groups R¹ canbe varied to provide compositions of Formula I having a weightaveragemolecular weight of from about 200 to about 3000. In onepreferred embodiment, the weight average molecular weight of thecompositions of Formula I is within a range of from about 800 to about2000. The hydrocarbon-soluble trimetalated 1-alkyne compositionscharacterized by Formula I can be obtained by reacting a 1-alkynecontaining at least 4 carbon atoms, an organometallic compound R°M, anda conjugated diene at a temperature above about 70° C., wherein the moleratio of R°M to 1-alkyne is about 3:1. The 1-alkyne may be representedbythe formula

    RCH.sub.2 C≡CH                                       (II)

wherein R is a hydrocarbyl group. Representative examples of such1-alkyne compounds include 1-butyne; 1-hexyne; 1-octyne; 1-decyne,1-dodecyne; 1-hexadecyne; 1-octadecyne; 3-methyl-1-butyne;3-methyl-1-pentyne; 3-ethyl-1-pentyne; 3-propyl-6-methyl-1-heptyne;3-cyclopentyl-1-propyne; etc.

The organometallic compound may be represented by the formula R°Mwherein R° is a hydrocarbyl group which may be a saturated aliphaticgroup, a saturated cycloaliphatic group, or an aromatic group.Generally, R° will contain up to about 20 carbon atoms. M is an alkalimetal including lithium, sodium, potassium, rubidium, cesium andfrancium. Representative examples of the organometallic compound R°Minclude: methylsodium, ethyllithium; propyllithium; isopropylpotassium,n-butyllithium, s-butyllithium; t-butylpotassium; t-butyllithium;pentyllithium; n-amylrubidium; tert-octylcesium; phenyllithium;naphthyllithium; etc. The conjugated dienes which are reacted with theintermediate to form the desired compositions are preferably1,3-conjugated dienes of the type which have been described above.

In a preferred embodiment, the trimetalated 1-alkyne catalysts arepreparedby the method which comprises the steps of

(a) reacting a 1-alkyne with an organometallic compound R°M in a moleratio of about 1:3 to form an intermediate, and

(b) reacting said intermediate with a conjugated diene at a temperatureof at least about 70° C. The mole ratio of conjugated diene to 1-alkynein the reaction is at least about 2:1 and may be as high as about30:1.More generally, the ratio will be in the range of from about 8:1 to20:1.

The reaction of the 1-alkyne with the organometallic compound followedby reaction with the conjugated diene can be carried out in the presenceof an inert diluent, and particularly, in the presence of a hydrocarbonsuch as an aliphatic, cycloaliphatic or aromatic hydrocarbon.Representative examples of suitable hydrocarbon diluents includen-butane, n-hexane, isooctane, decane, dodecane, cyclohexane,methylcyclohexane, benzene, toluene, xylene, etc. Preferred hydrocarbonsare aliphatic hydrocarbons containing from four to about 10 carbon atomsper molecule. Mixtures of hydrocarbons can also be utilized.

The reaction between the 1-alkyne and the organometallic compound toform the intermediate can be effected at temperatures of 20°-30° C., andthe reaction is generally conducted in an inert atmosphere such asundernitrogen. The reaction generally is conducted at atmospheric pressure.The intermediate obtained from the first step is a trimetalated alkynewhich is either insoluble or only slightly soluble in hydrocarbons,

The reaction between the intermediate and the conjugated diene to form ahydrocarbon soluble product is conducted at a temperature above 70°C.and more generally at a temperature of from about 70° C. to about150° C.The reaction generally is completed in less than about 5 hours, and thereaction results in a change in the color of the solution from a yellowto red or reddish brown. At about 80° C. the reactionis completed inabout 3 hours. At higher temperatures, the reaction is completed in lessthan 3 hours. If the reaction mixture is heated for too long a period,the catalytic activity of the resulting product may be reduced. Theproduct of this reaction is a trimetalated alkyne containing twodivalent oligomeric hydrocarbyl groups comprising moieties derived fromthe conjugated diene. Relatively small amounts of the conjugated dieneare reacted with the intermediate in the second step. The mole ratioofconjugated diene to 1-alkyne in the intermediate is at least about 2:1and may be as high as 30: 1. In one preferred embodiment, the mole ratioof conjugated diene to 1-alkyne is in a range of from about 8:1 to about20:1.

The trimetalated compounds used in this invention contain active as wellasinactive metal. The presence of at least two different types of carbonmetal linkages in the compositions of this invention can be shown byboth chemical and physical evidence. Gilman titration with allyl bromidedistinguishes between metal acetylide (--C≡C--M) which is Inactive andother carbon metal linkages (--C--C--M) which are active, J. OrganometalChem., 1 (1963) 8. Titration of the compositions of this invention showabout 67% of the total carbon-metal linkages are "active" correspondingto trimetalated alkynes. Ultraviolet and visible spectral studies showpeak absorbances at 300-340 NM and 400-450 NM for the compositions ofthis invention corresponding to inactive and active metal linkages,respectively.

An important property of these catalyst compositions is that they aresoluble in hydrocarbon solvents. The terms "soluble in hydrocarbonsolvents" and "hydrocarbon soluble" as used in the specifications andclaims indicate that the materials (polymer) are soluble inhydrocarbons, particularly aliphatic hydrocarbons such as n-hexane, tothe extent of at least about 5 grams of material per 100 grams ofsolvent at about 25° C. The solutions are stable in an inert atmosphereat room temperature for an extended period of time.

The following examples illustrate the preparation of the hydrocarbonsoluble trimetalated 1-alkyne compositions useful as catalysts.

Additional examples or useful catalysts are found in copending U.S. Pat.No. 5,147,051. The disclosure of this patent is hereby incorporated byreference for its description of additional catalysts.

Unless otherwise indicated in the following examples and elsewhere inthe specification and claims, all parts and percentages are by weight,temperatures are in degrees centigrade and pressure is at or nearatmospheric pressure.

EXAMPLE A

To a solution of 0.55 ml. of 1-octyne (3.73 mM) in dry hexane containedin a 7-ounce bottle equipped with rubber liner and three-hole crown capare charged 7 ml. of n-butyllithium (11.2 mM, 1.6M solution) through adisposable syringe at room temperature under nitrogen. The resultingslurry is shaken vigorously to complete the reaction, and the resultingpale yellow solution is allowed to stand at room temperature for onehour.To this solution is charged 25 gms. of 1,3-butadiene in hexane(24.2% butadiene, 112 mM butadiene). The mixture is tumbled in a bathheated to about 80° C. for three hours, and the resulting reddish brownsolution is cooled and stored. Analysis of the solution obtained in thismanner but the Gilman technique indicates active carbon-lithium linkageof63.6%. The calculated active carbon-lithium linkage based on1,3,3-trilithio-octyne is 66.7%.

EXAMPLE B

To a one-gallon reactor equipped with thermometer, stirrer, heatingmeans, pressure means, inlet and outlet ports are charged 450 gms. ofdry hexane,436 gms. (1008 mM) of n-butyllithium (1.54M) in hexane, and asolution of 37 gms. (336.3 mM) of 1-octyne in 35 gms. of dry hexane. Thereaction mixture is maintained under a nitrogen atmosphere as then-butyllithium and octyne are added to the reactor. After the aboveingredients are addedto the reactor, the mixture is stirred at roomtemperature for 30 minutes under nitrogen, and 816.5 gms. of a1,3-butadiene/hexane blend containing 200 gms. of 1,3-butadiene areadded to the reactor. This mixture is stirred at 85° C. for 120 minuteswhereupon a homogeneous reddish-brown solution is obtained. Thissolution is allowed to cool to room temperature and transferred tostorage tank under a nitrogen atmosphere. Gilman's titration indicatesthe presence of 62.34% active carbon-lithium linkages at 0.2628molarity. The calculated active carbon-lithium linkage is 66.7%.

Two-hundred grams of the catalyst solution is coagulated with excessmethanol in the presence of an antioxidant (e.g., 1%di-tertiary-butyl-para cresol). The resulting oily product is dried at50° C. under vacuum. Gel permeation chromatography analysis of theproduct indicates a 1123 Mw.

Polymerization

The copolymers useful in the present invention are prepared bypolymerizingthe conjugated diene and the vinyl aromatic compound in ahydrocarbon solvent in the presence of the above-described trimetalated1-alkyne catalyst. The polymerization temperature may range from about0° C.to about 160° C. or higher, but generally, the polymerization isconducted at a temperature of between about 75° C. and 150° C. for aperiod of from about 10 minutes to 2 or 3 hours. In a preferredembodiment, the polymerization is conducted at a temperature in thevicinity of about 100° C. for a period of about 15 minutes to one hour.The desired ultra high molecular weight copolymers can be obtainedconsistently at this relatively high temperature in a relatively shortperiod of time. Effecting polymerization with about 100% conversion inonehour or less allows for more effective use of labor and equipmentwhich represents a substantial savings in the commercial production ofthe copolymers. The copolymers may be random or block copolymers, butrandom copolymers are preferred.

The actual temperature utilized in the polymerization reaction willdepend upon the desired polymerization rate, the product desired, andthe particular catalyst or catalyst system utilized. The polymerizationmay beconducted under a negative pressure or an elevated pressure toavoid a lossof monomer and solvent, particularly when the temperaturesused are at or above the boiling point of either or both. Also, an inertatmosphere such as nitrogen can be used, and the usual precautions aretaken to exclude materials such as water and air that will inactivate orpoison the catalyst.

The polymerization reaction is generally conducted in a hydrocarbonsolventor diluent. Various hydrocarbon solvents can be used includingaliphatic, cycloaliphatic and aromatic hydrocarbons. In one embodiment,aliphatic hydrocarbons such as hexane and cyclohexane are preferred.Examples of thealiphatic hydrocarbons useful as solvent/diluent in thepolymerization reaction generally will contain from about 3 to about 20carbon atoms, andmore preferably from about 5 to about 10 carbon atoms.Examples of such aliphatic hydrocarbons include butane, pentane, hexane,heptane, octane, decane, etc. Cycloalkanes containing from 5 to 20 andpreferably from 5 toabout 10 carbon atoms also are useful. Examples ofsuch cycloalkanes include cyclopentane, cyclohexane, methyl cyclohexane,and cycloheptane. Aromatic solvents which may be utilized includebenzene, toluene and xylene. Individual diluents can be employed, orcombinations of hydrocarbons such as a hydrocarbon distillate fractionmay be utilized.

In many applications, it is desirable to increase the ratio of1,2-structure in the copolymers In order to increase the cure rate infreeradical cure systems. Various compositions, referred to in the artas modifier compositions, can be included in the copolymerizationmixture to increase the amount of 1,2-structure in the copolymers. Anyof the modified compositions which have been described in the prior artwhich will combine with the trimetalated 1-alkyne catalyst of thepresent invention to produce ultra high molecular weight copolymershaving increased amounts of 1,2-structure can be utilized in the methodof the present invention. Modifier compounds which have been found to beparticularly useful in combination with the trimetalated 1-alkynecatalystare those selected from the group consisting of linear andcyclic oligomeric oxolanyl alkanes. These types of modifier compoundsare described in U.S. Pat. No. 4,429,091, and the disclosure of U.S.Pat. No. 4,429,091 relating to such modifier compositions, particularlythe disclosure in Cols. 3 and 4, is hereby incorporated by reference.The oxolanyl modifiers can be prepared, for example, by reacting furanwhich is unsubstituted in either or both of the 2- or 5-positions, witheither an aldehyde or a ketone (e.g., acetone) in the presence of anacid such ashydrochloric acid. Control of the reaction parametersresults in the production of a product containing up to 95% of dimers,trimers and tetramers. Once the linear oligomers or cyclic structuresare formed, these reaction products are hydrogenated in the presence ofsuitable hydrogenation catalysts such as nickel base catalysts toproduce the desired oxolanyl compounds.

Examples of oligomeric modifiers for use with the trimethylated 1-alkynecatalysts of the present invention include: bis(2-oxolanyl)methane;2,2-bis(2-oxolanyl) propane; 1,1-bis(2-oxolanyl) ethane;2,2-bis(2-oxolanyl) butane; 2,2-bis(5-methyl-2-oxolanyl)propane; and2,2-bis(3,4,5-trimethyl-2-oxolanyl)propane.

The molar ratio of the oxolanyl modifiers to the trimetalated 1-alkynecatalyst can vary from about 1:20 to about 20:1, more often from about1:10 to 10:1. In one preferred embodiment, the molar ratio is from about0.5:1 to 3:1.

Other materials useful as modifiers in the process of this inventioninclude Lewis bases which may be, for example, ethers or tertiaryamines. Specific examples of such modifiers include diethyl ether,dibutyl ether, tetrahydrofuran, 2-methoxytetrahydrofuran,2-methoxymethyl tetrahydrofuran, 2,2'-di(tetrahydrofuryl) propane,ethyleneglycol dimethylether, ethyleneglycol diethylether,ethyleneglycol dibutylether and the like; triethylamine,1,2-dipiperidinoethane, pyridine, N,N,N',N'-tetramethylethylenediamine,N,N,N',N'-tetraethylenediamine, N-methylmorpholine, triethylenediamine,tripiperidinophosphine oxide and the like.

The amounts of trimetalated 1-alkyne catalyst and the optionalmodifier(s) utilized in the polymerization reaction are amounts designedto result in the formation of a copolymer having the desired propertiesdescribed above. The amounts utilized in a particular copolymerizationreaction willdepend upon a number of factors including the types andamounts of monomersbeing copolymerized, the desired molecular weight andmolecular weight distribution, etc. One of the desirable features of thecatalyst used in the method of the invention is that only small amountsof the catalysts are required to produce the desired copolymer, and thisresults in a cost savings.

The millimole ratio of the catalyst to the weight of the monomers whichis employed in the preparation of the copolymers is expressed as thenumber of millimoles of active metal in the catalysts based on metal per100 grams of monomer (PHGM). In the trimetalated 1-alkyne catalyst ofthe present invention wherein the metals are in the 1,3,3-positions, themetalin the 1-position is inactive whereas the metals in the 3-positionare active metals. Generally, the ratio of millimoles of active metalPHGM mayrange from about 0.4 to about 0.7. At the higher ratios, theweight averagemolecular weight of the copolymers of the presentinvention tends to decrease. Thus, in one preferred embodiment, theratio of millimoles of active metal PHGM will range from about 0.45 toabout 0.65.

The term 1,2-units or 1,2-microstructure as used in the presentapplicationrefers to the mode of addition of a growing polymer chainwith a conjugateddiene monomer unit. Either 1,2-addition or 1,4-additioncan occur. In termsof nomenclature, this results in a 1,2-unit ormicrostructure for the monomer unit in the polymer chain when1,3-butadiene is a monomer. When isoprene is the monomer,3,4-microstructure most generally results with a smaller amount of1,2-microstructure in the polymer chain. Naming of the polymer structurewhich results from 1,2-addition is thus dependent on themonomers beingpolymerized. For simplicity, the term 1,2-unit or 1,2-microstructure isemployed to determine the microstructure which results from 1,2-additionof conjugated dienes. The microstructure of the ultra high molecularweight copolymers of the present invention is determined using protonNMR. The copolymers useful in this invention can be prepared containingrelatively high amounts of 1,2 units (vinyl) such as from 30 to 80% byweight of 1,2 units.

Samples may be withdrawn from the reactor periodically during thepolymerization reaction to determine percent conversion (by measuringthe total solids), color and character of the reaction mass. Thereaction timeof the polymerization is dependent upon several factorsincluding the polymerization temperature and the catalyst concentration.Generally complete conversion to polymer can be obtained at temperaturesof about 100° C. in about 15 minutes to one hour.

When the polymerization reaction has progressed to the desired degree,the product can be dropped from the reactor or combined with an alcoholsuch as methanol or isopropanol, or other liquid medium whichdeactivates the initiator and coagulates and precipitates the polymerproduct. Generally, an amount of isopropanol equal in weight to theamount of diluent (e.g., hexane) used is sufficient to effectcoagulation and precipitation. It is also customary and advantageous toinclude an antioxidant such as about 1%of di-tertiary butyl paracresolin the isopropanol. The polymer product is recovered and dried to removesolvent.

Since the initially formed and unquenched polymer solutions obtained inaccordance with the method of the invention contain terminal metal atoms(e.g., lithium atoms) on the polymer molecules, the unquenched polymersolutions can be treated with various reagents to introduce functionalgroups by replacing the terminal metal atoms. For example, theunquenched copolymer solutions can be treated with various reagents tointroduce terminal functional groups such as --SH, --OH, --COOH,halogen, etc. Carboxyl groups can be introduced by treating theunquenched solution withcarbon dioxide, and hydroxy groups can beintroduced by treating the unquenched polymer solution with epoxycompounds. The procedures for introducing such groups into theunquenched copolymer solutions containingterminal metal atoms are wellknown to those skilled in the art.

The molecular weights and the dilute solution viscosity (DSV) in tolueneofthe copolymers reported herein, are determined by techniques describedin U.S. Pat. No. 5,147,951. The disclosures regarding molecular weightand DSV determinations are hereby incorporated by reference.

The intrinsic viscosity (η) of the copolymers used in the presentinvention is determined by the general procedure utilized for DSV exceptthat the intrinsic viscosity is the average of four data points obtainedwith four different concentrations.

The glass transition temperature (Tg) of the copolymers used in thepresentinvention is determined using a DuPont 1090 thermal analyzer witha 910 Differential Scanning Calorimeter System and following themanufacturer's recommended procedure. The onset, inflection and offsettemperatures are calculated in accordance with the Interactive DSC DataAnalysis-Program V2D.

The relaxation properties of the copolymers used in the presentinvention are determined using a Bendix Scott STI/200 Mooney Viscometerand a modification of the conventional method for measuring the"shearing viscosity" of rubber and rubber-like materials such as SBR. Inthis procedure, the sample is placed between the platens which are thenclosed.The sample is warmed at 100° C. for one minute, and the rotor isturned on. After four minutes, the Mooney value (ML₁₊₄) is determinedandthe rotor is turned off. Measurement of the relaxation is begun, and arelaxation time (AL₈₀) is recorded when the torque reaches 20% (T₈₀) ofthe Mooney value ML₁₊₄. After a total of 10 minutes, the torque is againobserved and recorded as AL₁₊₄₊₅, and the platensare opened. The percentrelaxation is calculated as follows: ##EQU1##A typical graph of thetorque versus time for this test procedure is shown in the drawingwherein the various values utilized in computation of percent relaxationsuch as ML₁₊₄ and AL₁₊₄₊₅ are noted. In general, the copolymers used inthe present invention are characterized bya percent relaxation asdefined above of from about 20% to about 80%. More often, the percentrelation will be between about 30 or even 40% and about70%. The Mooneyviscosity (ML₁₊₄ @100° C.) of the copolymers isgreater than 200.

The following examples illustrate the copolymers useful in the presentinvention and methods for their preparation. Additional examples ofcopolymers are found in U.S. Pat. No. 5,147,951. The disclosure of thispatent is hereby incorporated by reference for its description ofadditional coplymers.

Unless otherwise indicated in the following examples and elsewhere inthe specification and claims, values for number average molecular weight(Mn) and weight average molecular weight (Mw) are determined intetrahydrofuranusing GPC as described above. The microstructure of thecopolymers (e.g., 1,4 units, 1,2 units, etc., is determined utilizingproton NMR in carbon disulfide.

EXAMPLE 1

To a two-gallon stainless steel reactor equipped with thermometer,stirrer,heating means, pressure means, inlet and outlet ports which ismaintained under a nitrogen atmosphere, there are charged 4190 grams ofa styrene/butadiene/hexane blend containing 155.3 grams of styrene and622.3grams of 1,3-butadiene, 9.25 ml. of 2,2'-di(tetrahydrofuryl)propane in 20 ml. of hexane, and 17.5 ml. of the uncoagulated catalystsolution of Example B (0.211 molar solution in hexane). Thepolymerization is conducted at 100° C. for 60 minutes. The resultingcopolymer is dropped into a five-gallon container equipped withpolyethylene liner and containing two gallons of hexane, about 1% ofdi-tertiary butyl-para-cresol and 25 ml. of a short-stop. The physicalproperties of the polymer prepared in this manner are summarized in thefollowing Table II.

                  TABLE II                                                        ______________________________________                                        ML.sub.1+4 (@ 100° C.)                                                                   >200                                                        GPC Analysis                                                                  Mn (× 10.sup.-4)                                                                          44.5                                                        Mw (× 10.sup.-4)                                                                          111.4                                                       Mw/Mn             2.5                                                         [η].sub.THF   7.55                                                        DSV               6.72                                                        % Gel             0.00                                                        Wt. % Styrene     21.6                                                        Wt. % Block Styrene                                                                             0.00                                                        Wt. % 1,2 (Bd Base)                                                                             46.0                                                        Tg (°C.)   -49.9                                                       ______________________________________                                    

EXAMPLE 2

Example 1 is substantially repeated with the exception that the blendconsists of 4.43% styrene, 14.18% 1,3-butadiene, 81.39% hexane, thetotal amount of blend charged is 4287 grams, and 7.6 mM of2,2'-di(tetrahydrofuryl) propane and 3.8 mM of the catalyst of Example Bare employed.

The resultant copolymer shows a styrene content of 25.2% by weight, a1,2-microstructure content in the butadiene portion of 48.3% (based onbutadiene=100); a DSV of 5.12 dl/g with no gel; [η]_(THF) of 5.98; ML₁₊₄at 100° C. ≧7200; a weight average molecular weight (Mw) of 1,191,358; aMw/Mn ratio of 2.99 as determined by GPC; and a Tg of -45.7° C.

EXAMPLES 3-4

Example 1 is substantially repeated with the exception that the blendcomposition is varied in each polymerization. Hexane, styrene,1,3-butadiene in the amounts shown in Table III are placed in a twogallonreactor under a nitrogen atmosphere. The polymerization is carriedout for 60 minutes under the conditions shown in Table III.

                  TABLE III                                                       ______________________________________                                                         3       4                                                    ______________________________________                                        Polymerization Conditions                                                     Hexane (g)         3745      3745                                             Styrene (g)        154       270                                              1,3-Butadiene (g)  618       533                                              Modifier (mM)      9.25      7.40                                             Initiator (mM)     3.69      3.08                                             Polymerization Temperature                                                    Initiation Temp. (°C.)                                                                    20        20                                               Set Temp. (°C.)                                                                           110       120                                              Max. Temp. (°C.)                                                                          149       140                                              Polymerization Conversion (%)                                                                    100       100                                              Properties of Polymer                                                         Wt. % Styrene      21.6      35.7                                             Wt. % 1,2 (100% Bd Base)                                                                         52.6      45.5                                             ML.sub.1+4 @ 100° C.                                                                      >200      >200                                             ______________________________________                                    

EXAMPLES 5-7

Example 1 is substantially repeated with the exception that the blendcomposition is varied in each polymerization. The amounts of hexane,styrene and 1,3-butadiene and the reaction conditions are shown in TableIV.

                  TABLE IV                                                        ______________________________________                                                        5      6        7                                             ______________________________________                                        Polymerization Conditions                                                     Hexane (g)        3745     3745     3745                                      Styrene (g)       270      270      270                                       1,3-Butadiene (g) 533      533      533                                       Modifier (mM)     8.68     5.20     8.70                                      Active Li (mM)    3.47     3.47     2.76                                      Polymerization Temperature                                                    Initiation Temp. (°C.)                                                                   20       20       20                                        Set Temp. (°C.)                                                                          120      120      120                                       Max. Temp. (°C.)                                                                         134      137      140                                       Polymerization Conversion (%)                                                                   100      100      100                                       Properties of Polymer                                                         Wt. % Styrene     36.1     35.5     35.4                                      Wt. % 1,2 (100% Bd Base)                                                                        59.2     45.9     45.6                                      Mn (× 10.sup.-4)                                                                          45.9     44.6     60.1                                      Mw (× 10.sup.-4)                                                                          123.4    156.3    164.5                                     Mw/Mn             2.69     3.50     2.74                                      ML.sub.1+4 @ 100° C.                                                                     >200     >200     >200                                      ______________________________________                                    

EXAMPLE 8

The procedure of Example 1 is repeated except that blend composition isvaried. The resultant copolymer shows: a styrene content of 21.6%; a 1,2microstructure content of 46.0%; [η]_(THF) of 7.35; and ML₁₊₄ at 100° C.of >200.

(B) Oil.

The second component of the elastomer compositions of the presentinventionis oil which serves as an extender of the above-describedcopolymers. Any oil which is compatible with and capable of extendingthe ultra high molecular weight copolymer compositions can be used inthe preparation of the elastomer compositions of the present invention.Thus, the oils may beeither natural or synthetic oils provided that theyare compatible with thecopolymers and capable of extending thecopolymers. Natural oils, and in particular, petroleum base oils such asmineral oils, are preferred types of oil useful in the presentinvention. The oils may be naphthenic oils, paraffinic or aromatic oils.These oils are substantially hydrocarbon oils, often hydrocarbon mineraloils, usually petroleum base oils. A number of specific useful oils aredisclosed in U.S. Pat. No. 2,964,083, and in particular in Table 1 incolumns 9-12 and U.S. Pat. No. 4,748,199, column 5 line 27-37. Thesepatents are hereby incorporated by reference for their disclosure ofspecific oils useful as extenders in this invention.

The American Society for Testing and Materials has suggested andpublished the following classification for oil types (ASTM designation,D-2226).

    ______________________________________                                              Asphaltenes Polar Compounds                                                                            Saturated Hydro-                               Types max., %     max., %      carbons, %                                     ______________________________________                                        101   0.75        25           20 max.                                        102   0.5         12           20.1 to 35                                     103   0.3          6           35.1 to 65                                     104   0.1          1           65 min.                                        ______________________________________                                    

The alternative classification of highly aromatic, aromatic, naphthenic,and paraffinic corresponds to the 101, 102, 103 and 104 types,respectively.

Most often, the oils will be blends comprising various mixtures ofnaphthenic, or paraffinic or aromatic oils. In one embodiment, the oilshould have a boiling point above 230° C. and preferably above 290° C.Mineral oils having low aniline point or high aromatic content arepreferred, particularly when the rubber contains high amounts of styreneand other aromatic components. Aromatic oils generally are characterizedas having a viscosity gravity content (VGC) as determined byASTMprocedure D-2501 of from 0.900 to 1.100. Naphthenics and paraffinsgenerally have a VGC of less than 0.900.

The particular oil which is selected for blending with the copolymerswill be determined by the intended use of the rubber article beingproduced. For example, where the oil extended composition is to be usedfor tires utilized in cold climates, it is desired that the rubbertreads have low temperature flexibility, and this may be accomplished byutilizing hydrocarbon oils of low pour point. In such instances, theoils may have boiling points lower than the 230° C. indicated above.

It has been discovered that the elastomers of the present inventioncomprising the above-described copolymers and oil can be preparedcontaining very large amounts of oil, and in particular, the elastomercompositions of the present invention can be prepared containing from 30or 50 to about 300 parts of oil per 100 parts of copolymer without lossofdesirable properties. Blends comprising 80, 100, 150 or even 250 partsof oil per 100 parts of copolymer are easily prepared and have beenfound to exhibit desirable and useful properties.

The elastomer compositions of the present invention comprising blends ofcopolymer and oil can be prepared by any of the techniques known tothose skilled in the art. For example, the blends can be prepared onroll mills or in internal mixers such as a Banbury mixer. When it isdesired to prepare elastomer compositions of the present inventioncontaining high amounts of oil, the oil may be blended with thecopolymer with incrementaladditions of the oil or with a single additionof the oil. Alternatively, the oil can be added to a latex of thecopolymer.

The elastomer compositions comprising the copolymers (A) and the oil (B)are useful in a variety of applications such as in the formation of loadbearing or damping materials such as may be utilized as dampers forlarge structures such as towers and buildings. Vulcanizable compositionscomprising the elastomer compositions of the present invention can beutilized in tires, fenders, belts, hoses, window frames and otherindustrial products. The elastomer compositions of the present inventionalso may be compounded to form compositions which are not curable, andsuch compositions can be utilized in applications such as sealants,caulks, adhesives, etc.

When curing agents are mixed with the elastomer compositions of thepresentinventions they may be conventional types such as sulfur- orperoxide-basedcuring systems. They are used in conventional amounts andincorporated in the uncured compositions of the invention by knowntechniques and procedures. Fillers may be, and often are present as isknown to those skilled in the art. Typical fillers include carbonblacks, glass, silica, talc and similar finely divided mineralmaterials. In addition to the fillers, other materials normally used inconventional rubber formulationssuch as antioxidants, accelerators,retarders, promoters and the like may be incorporated into thecompositions of the invention.

The vulcanizable (curable) compositions containing the elastomercompositions of the present invention can be prepared by conventionaltechniques using various types of mills, blenders and mixers known inthe art. The cured compositions can be made by the same techniquesfollowed bycuring.

The temperature used in formulating the elastomer compositions of thisinvention range from ambient to those normally used in the art such as75°-175° or even higher depending upon a particular modifiedelastomercomposition being processed. Because of the sheer forces involvedinformulating the elastomer compositions, the formulation process isexothermic and high temperatures are normal.

The vulcanizates of the present invention are made by vulcanizing amixturecomprising at least one of the elastomer compositions of theinvention, fillers, conventional curing systems and agents such assulfur, antioxidants, accelerators, retarders, coupling agents,promoters, etc. The vulcanizates are prepared by curing thesecompositions under conditions of temperature and time customarily usedin the art. Typically,the elastomer composition and fillers are mixed,the sulfur and accelerators are added, and the mixture is cured.

The following examples illustrate the various elastomer compositions ofthepresent invention.

EXAMPLE I

The hexane-diluted product obtained in Example 1 is extended with 130partsof an aromatic oil per 100 parts of the copolymer followed bydrum-drying. Whereas the Mooney viscosity (ML₁₊₄ @100° C.) of thecopolymerof Example 1 is greater than 200, the Mooney viscosity of theoil extended copolymer of this example is 31.5. The glass transitiontemperature of theoil extended copolymer is -47.5° C.

EXAMPLE II

The copolymer prepared in Example 2 is extended with a naphthenic oil(Flexon 641 from Exxon Oil Co.) and an aromatic oil (Sundex 750T fromSun Refining and Marketing Company) at different oil levels, and theMooney viscosity and the processability of the resulting elastomer aredetermined. The processability or workability of the polymer isevaluated using 8-inch rolls of a drum-dryer at a constant 150° C.Evaluationfor polymer recovery is made in accordance with the 5-pointmethod wherein point 1 (worst) is given to a sample exhibiting such highadhesion that atthe end of the test, it is very difficult to peel thesample from the roll surfaces. The different oil levels and the resultsobtained are summarizedin the following Table V.

                  TABLE V                                                         ______________________________________                                                            ML.sub.1+4                                                                              Polymer Recovery                                Type of Oil                                                                             PHR       @ 100° C.*                                                                       (Drum-Dry)                                      ______________________________________                                        Naphthenic Oil                                                                          37.5      >200.0    5                                                         60.0      68.3      5                                                         80.0      56.4      5                                                         100.0     40.1      4                                                         120.0     35.5      3                                               Aromatic Oil                                                                            37.5      >200.0    5                                                         60.0      67.5      5                                                         80.0      55.7      5                                                         100.0     46.1      5                                                         120.0     39.0      4                                                         150.0     30.4      2                                               ______________________________________                                        *Mooney Viscosity; Bendix Scott STI/200                                   

EXAMPLES III-VI

The copolymers of Examples 3-7 are blended with various amounts ofSundex 750T oil as shown in Table VI, and the Mooney viscosity andprocessabilityfor polymer recovery are determined. The results of thesedeterminations are summarized in the following Table VI.

                  TABLE VI                                                        ______________________________________                                                Copolymer of                                                                             Oil           Polymer                                      Example Example    PHR     ML.sub.1+4                                                                          Recovery Rating                              ______________________________________                                        III     3           80     62.8  5                                                               100     48.8  5                                                               150     30.4  2                                            IV      4          215     17.0  1                                            V       5          152     24    2                                            VI      6          100     39    5                                            VII     7          150     28    3                                            ______________________________________                                    

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications as fall withinthe scope of the appended claims.

We claim:
 1. An elastomer composition comprising(A) an ultra highmolecular weight copolymer composition of a 1,3-conjugated diene and anaromatic vinyl compound having a weight average molecular weight ofgreater than about 1,000,000 and a vinyl content in the diene base offrom 30 to 80% by weight; and (B) from about 30 to about 300 parts byweight of oil per 100 parts by weight of the copolymer (A).
 2. Theelastomer of claim 1 wherein the oil is at least one naphthenic,paraffinic or aromatic oil or mixtures thereof.
 3. The elastomercomposition of claim 1 comprising at least about 80 parts by weight ofthe oil per 100 parts by weight of elastomer.
 4. The elastomercomposition of claim 1 wherein the weight average molecular weight ofthe copolymer (A) is greater than 1,100,000.
 5. The elastomercomposition of claim 1 wherein the intrinsic viscosity intetrahydrofuran of the copolymer (A) is at least about 4.0.
 6. Theelastomer composition of claim 1 wherein the dilute solution viscosityin toluene of the copolymer composition is at least about 3.5 dl/g. 7.The elastomer composition of claim 1 wherein the copolymer (A) comprisesat least 30% by weight of a high molecular weight copolymer fractionhaving a number average molecular weight of greater than 1,000,000 andless than about 8% by weight of a low molecular weight copolymerfraction having a number average molecular weight of less than 100,000.8. The elastomer composition of claim 1 wherein the copolymer (A)comprises from about 50 to about 90% by weight of the conjugated dieneand from about 10 to about 50% by weight of the aromatic vinyl compound.9. The elastomer composition of claim 1 wherein the conjugated diene of(A) is 1,3-butadiene, isoprene or piperylene.
 10. The elastomercomposition of claim 1 wherein the aromatic vinyl compound of (A) is astyrene.
 11. The elastomer composition of claim 1 wherein copolymer (A)is obtained by polymerizing a mixture of 1,3-butadiene and a styrene.12. The elastomer composition of claim 1 wherein the Mw/Mn ratio ofcopolymer (A) is from 2.0 to 5.0.
 13. The elastomer composition of claim1 wherein the Mw/Mn ratio of copolymer (A) is from 2.5 to 5.0.